Network Topology

Network topology is the arrangement of the various elements (links, nodes, etc.) of a computer

network.
Essentially, it is the topological structure of a network and may be depicted physically or logically.
Physical topology is the placement of the various components of a network, including device location and cable installation, while logical topology illustrates how data flows within a network, regardless of its physical design.
Distances between nodes, physical interconnections, transmission rates, or signal types may differ between two networks, yet their topologies may be identical.
The study of network topology recognizes eight basic topologies: point-to-point, bus, star, ring or circular, mesh, tree, hybrid, or daisy chain.

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ASCII Code

The American Standard Code for Information Interchange (ASCII)  is a character-encoding scheme originally based on the English alphabet that encodes 128 specified characters - the numbers 0-9, the letters a-z and A-Z, some basic punctuation symbols, some control codes that originated with Teletype machines, and a blank space - into the 7-bit binary integers.

ASCII codes represent text in computers, communications equipment, and other devices that use text. Most modern character-encoding schemes are based on ASCII, though they support many additional characters.

 

ASCII developed from telegraphic codes. Its first commercial use was as a seven-bit teleprinter code promoted by Bell data services. 

ASCII includes definitions for 128 characters: 33 are non-printing control characters that affect how text and space are processed and 95 printable characters, including the space

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Computer applications and products

Preparatory Materials on computer applications and products:

1. The Apache Web Server: Apache is a widely-used free HTTP server. It was originally developed on top of the NCSA httpd server as a series of patches; hence came to be called ""a patchy server"", which later became the name ""Apache."" The first public release of Apache (version 0.6.2) came out in April 1995. Version 0.8.8 release, based on the new server architecture, codenamed Shambhala and designed by Robert Thau, was also released in 1995. Websites: Apache Software Foundation, Apache History - Timeline.

2. HotJava, a Java-based web browser, was developed by Patrick Naughton and Jonathan Payne (a Sun engineer) in 1994. It was initially named WebRunner.

 

3. MP3 is short for MPEG Audio Layer 3 -- where MPEG stands for Motion Picture Experts Group -- and it is a compression format for digital audio files. MP3 is the result of the work of Karlheinz Brandenburg at the Frauenhofer Institute in Erlangen, Germany in joint co-operation with Prof. Dieter Seitzer of University of Erlangen. The MP3 patent was awarded to Frauenhofer Institute in 1989. In 1997 Tomislav Uzelac, a developer at Advanced Multimedia Products, created the AMP Playback Engine for MP3. Justin Frankel and Dmitry Boldyrev added a Windows GUI to the AMP engine and created Winamp, which was offered as a free MP3 player. Links: MP3 Overview (lycos.com), Fraunhofer Institute website: History of MP3, Karlheinz Brandenburg and The Secret History of MP3 (bbc.co.uk), MP3 history with timeline by Yu-Chin Chang, Interview with Karlheinz Brandenburg (intel.com), Karlheinz Brandenburg speaks out (BBC News)

 

4. Microsoft Internet Information Server (IIS) was code named as 'Denali' during development.

5. Opera, the popular and fast Web browser: Jon S. von Tetzchner and Geir Ivarsøy started writing this browser in 1994 while working for Norwegian telecom Telenor. The company Opera Software ASA was founded in Oslo, Norway in 1995. The first public release was Opera 2.1 in 1996. Version 3 came in 1998, Version 4 in 2000 and Versions 5 and 6 in 2001.

6. Jaguar is the code name for Apple's operating system Mac OS X v10.2. The code name for Max OS X v10.0 was Cheetah and for v10.1 was Puma.

7. Pong is a computer game written by Nolan Bushnell in 1971.

8. PostScript, Photoshop, PageMill, Aldus PageMaker and Acrobat are all from Adobe.

9. Microsoft Powerpoint, the presentation software, was a product of Forethought, California. It was originally named as 'Presenter' and was designed for Windows 2.0. Two developers worked on a Lisa machine for 16 months to complete the first version PowerPoint 1, which was released in April 1987. Microsoft acquired Forethought in August 1987.

10. Pretty Good Privacy (PGP) was developed by Philip Zimmerman. It uses the RSA (Rivest-Shamir-Adleman) algorithm for encryption.

11. Sketchpad was the first computer graphics application. It was designed by Ivan Sutherland in 1963 on a TX-2 computer at Massachussets Institute of Technology (MIT).

12. TeX, the text formatter, and METAFOND was written by Donald Knuth. He also authored the book 'The Art of Computer Programming,' considered a must read for any Computer Science student. Links: Donald Knuth, a portrait

13. VERONICA stands for Very Easy Rodent-Oriented Netwide Index to Computerized Archives. It was one of the first search application on the primitive Internet.

14. Bill Joy: Wrote ed (editor for mortals), the UNIX text editor in 1975 and vi in 1978. In 1976, he wrote a Pascal compiler for UNIX. He also wrote the utilities rsh, rcp, rlogin and the first BSD (Berkeley Software Development) release of utilities.

15. Visicalc was the first spreadsheet application (Microsoft Excel is a popular example of spreadsheet software). It was written in 1979 first for the Apple II by Dan Bricklin and Bob Frankston and sold by Software Arts which the authors founded. VisiCalc was soon sold to Lotus Development Corporation, where it was developed into the Lotus 1-2-3.

16. Winamp, the popular MP3 player for Windows is developed by Nullsoft. The development of Winamp was started in 1997 by Justin Frankel in 1997. Nullsoft is now owned by AOL.

17. WordStar was originally written by Seymour Rubenstein. He formed MicroPro International Inc. in 1978. WordStar for CP/M was released by MicroPro in 1979. It was later ported to MS/PC DOS by Jim Fo

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Computer Peripherals

Preparatory Materials on computer peripherals:

• The Compact Disk (CD) was invented by James Russell in 1965. Russell holds 22 patents for different aspects of the technology.
• DVD or Digital Versatile Disc was mainly developed by the company Matshusita and it was announced in November 1995. There is no one person who can be called the inventor of DVD.
• The floppy was invented by IBM engineers led by Alan Shugart in 1971. The nickname ""floppy"" came from its flexibility. The first floppies were of 8"" diameter and were designed for loading microcodes into the controller of the Merlin (IBM 3330) disk pack file (a 100 MB storage device). The 5 1/4"" floppy was developed by Alan Shugart in 1976 for Wang Laboratories. The 3 1/2"" floppy drives and diskettes were introduced by Sony in 1981.
• Haptics is the science of applying touch (tactile) sensation and control to interaction with computer applications. The Wingman Force Feedback Mouse (WFFM) from Logitech is an example of a haptic device.

 

 

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Computer Virus

Preparatory Materials on computer peripherals:

• The first virus: Fred Cohen, a PhD student at University of South California, demonstrated the first documented computer virus on November 10, 1983 as an experiment in computer security. The name 'virus' was given by Len Adleman, Fred's seminar adviser. The virus was added to a graphics program called VD that ran on a VAX mini computer. Links: History of Viruses at cknow.com
• Prisilla is a PRI and Melissa variant
• Slammer or Sapphire is a worm (or a virus) program that attacks Microsoft SQL Server 2000 and MSDE 2000 - Microsoft Data Engine. It appeared in the early hours on 25th January 2003, although there are reports of it existing since 20th January. Links: Description of the Slammer worm at F-Secure website, Initial report of the Slammer or Sapphire Worm, at securityfocus.com.

 

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Microprocessor

Preparatory Materials on Microprocessor:

 

• Advanced Micro Devices (AMD) is the biggest competitor to Intel in the processor space. AMD processors include the K5, which was positioned against Intel's Pentium I; K6 which competed against Pentium II and Pentium MMX; Athlon or K7; Duron (originally code-named Athlon Select, then Spitfire), which is the low end of AMD's Athlon line, ClawHammer and Opteron.
• Crusoe: This low-power microprocessor ideal for mobile computing was released by Transmeta Corporation transmeta.com on January 19th, 2000. Links: Geek.com article on Crusoe.
• The name Pentium was selected during a contest among Intel employees in 1993. The first Pentium came out in 1994.
• Itanium is the first 64-bit microprocessor from Intel. McKinley is the successor version of Itanium. Other Intel chips include x86, Pentium, Celeron, Xeon, Atom.

 

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